1. Field of Industrial Application
The present invention relates to a liquid crystal display device comprising a back light including a liquid crystal display panel having a liquid crystal sealed between two superposed insulating substrates, a light guide plate arranged below the liquid crystal display panel, and a fluorescent tube arranged in the vicinity of the side of the light guide plate, and, more particularly, to a data processing device having said liquid crystal display device assembled as a display unit.
2. Prior Art
In a liquid crystal display device of active matrix type, nonlinear devices (e.g., switching devices) are disposed in a manner to correspond to a plurality of pixel electrodes arranged in matrix, respectively. The liquid crystal in each pixel is always drive, in principle, (at a duty ratio of 1.0). In comparison with the so-called xe2x80x9csimple matrix typexe2x80x9d which employs a time division driving system, therefore, the active system has better contrast and has become an indispensable technique particularly in a color liquid crystal display device. A typical example of the switching devices is a thin film transistor (TFT).
The liquid crystal display device is constructed to comprise: a liquid crystal display panel (or liquid crystal display element) prepared by superposing two transparent glass substrates at a predetermined gap such that their surfaces each having display pixel electrodes of a transparent conductive film and an orientation film laminated thereon are opposed to each other, by adhering the two substrates to each other by a seal member applied in a frame shape to the edge portion between the two substrates, by filling and sealing a liquid crystal from a liquid crystal sealing entrance formed in a portion of the seal member into the seal member between the two substrates, and by mounting or adhering a polarizing plate to the outer sides of the two substrates; a circuit substrate arranged outside of the outer peripheral portion of the liquid crystal display panel; an intermediate frame molded for holding the aforementioned individual members; a metallic shield casing formed with a liquid crystal display window for accommodating those individual members; and a back light arranged below the liquid crystal display panel for supplying a light to the liquid crystal display panel.
Here, the liquid crystal display device of active matrix type using the thin film transistors is known in Japanese Patent Laid-Open No. 309921/1988 or on pp. 193 to 210 of Nikkei Electronics entitled xe2x80x9cActive Matrix Type Color Liquid Crystal Display of 12.5 Type Adopting Redundant Constructionxe2x80x9d and issued on Dec. 15, 1986 NIKKEI McGRAW-HILL for example.
Problems to Be Solved by the Invention
The liquid crystal display device of the prior art is constructed such that vide signal lines are alternately extracted to the two opposed longer sides of the liquid crystal display panel and such that video signal line driving circuit substrates are individually arranged outside of the longer sides. As a result, the periphery of the display unit, i.e., the so-called xe2x80x9cframe portionxe2x80x9d cannot have its area reduced to raise a problem in which the liquid crystal display device or a data processing device such as a personal computer or word processor having the liquid crystal display device assembled therein as the display unit has its external size enlarged to have a heavy weight.
A first target the present invention is to solve the above-specified problem.
In the liquid crystal display device, on the other hand, in order that the liquid crystal display panel having the liquid crystal sealed between the two superposed transparent glass substrates may be fixed in that device, both the two transparent substrates are pushed through rubber cushions. As a result, the two transparent glass substrates are so severely pushed that the gap of the liquid crystal between the two transparent glass substrates is changed to raise a problem of a display unevenness. As a result, the liquid crystal display panel cannot be so firmly held that a sufficient mechanical strength cannot be retained.
A second target the present invention is to solve the above-specified problem.
In the liquid crystal display device of the prior art having the back light composed of a fluorescent tube and a light guide plate, on the other hand, a sufficient consideration has not been taken into the place for arranging the fluorescent tube or the like so that said device is not sufficiently small-sized and light-weighted yet. In accordance with the development of recent years in the computerized society, it is desired that the data processing device such as a personal computer or word processor be progressed to a portable one having the size of a notebook, and that the liquid crystal display device assembled as the display unit and mainly determining the shape, size and weight of the data processing device be small-sized and light-weighted.
A third target the present invention is to solve the above-specified problem.
In the prior art, on the other hand, in order that the light guide plate of the back light and the liquid crystal display panel may be firmly held in said device, there arises a problem that the device has its external size enlarged.
A fourth target the present invention is to solve the above-specified problem.
In the prior art, on the other hand, when two lamp cables, with which are individually connected the one-side ends of the fluorescent tube constituting the back light, are to be extracted in one direction, there is no space for threading the lamp cables to allow these cables to bulging out of the liquid crystal display device. Thus, a large space for accommodating the lamp cables to make it difficult to reduce the size and weight of the device. On the other hand, the rubber bushes of the prior art for holding the fluorescent tube are active to hold only the fluorescent tube.
A fifth target the present invention is to solve the above-specified problem.
On the other hand, the light guide plate of the back light of the prior art has many spare areas for holding the light guide plate in said device so that it is made far larger than an effective light emitting portion. As a result, there is a problem that the device is large-sized and heavy-weighted.
A sixth target the present invention is to solve the above-specified problem.
In the prior art, on the other hand, after the liquid crystal display device has been assembled, there is a problem that the monolithic mold casing (or frame body) has its bottom face caused to bulge by the downward force which is exerted upon the bottom face by the weight of the liquid crystal display panel, the light guide plane and so on. In order to suppress this bulge, the mold casing has to be thickened to disable the liquid crystal display device to be thinned and light-weighted.
A seventh target the present invention is to solve the above-specified problem.
In the liquid crystal display device of the prior art, on the other hand, the cables of the fluorescent tube of the back light extend along the outer side of said device so that said cables and an inverter to be connected wit the leading ends of the former bulge out of the device. Thus, there arises a problem that the external size is substantially enlarged.
An eighth target the present invention is to solve the above-specified problem.
In recent years, on the other hand, the liquid crystal display device of active matrix type using thin film transistors as its switching elements is demanded to have the multi-gradation and the single power source so that its performance and facility may be improved. However, the circuit for realizing those demands consumes much power. If, moreover, the circuit means is packaged in compact, the highly dense packaging results to raise a problem in the hear liberation in the parts packaged on the circuit substrate.
A ninth target the present invention is to solve the above-specified problem.
On the other hand, in case the number of electronic parts constituting the liquid crystal display panel driving circuit is large, the prior art is practiced, for example, by superposing the circuit substrates in two stages, by packaging the numerous electronic parts on the individual upper and lower faces of the two circuit substrates and by electrically connecting the two circuit substrates by joiners. According to this practice, however, the number of circuit substrate is increased, and the joiners have to be added to increase the cost for the material and the number of working steps. The resultant problem is a rise in the production cost.
A tenth target the present invention is to solve the above-specified problem.
FIG. 46 is an internal top plan view of an essential portion of the liquid crystal display device of the prior art.
Letters SHD designate a metallic shield casing; letters PNL designate a liquid crystal display panel; letters PCB1 and PCB 2 designate circuit substrates arranged in the outer peripheral portion of the liquid crystal display panel PNL; letters JN designate a joiner for electrically connecting the circuit substrates PCB1 and PCB2; letters SH designate mounting holes which are formed in the shield casing SHD for mounting said liquid crystal display device as the display unit in the data processing device such as a personal computer or word processor.
The mounting holes SH are usually formed in the four corners of the shield casing SHD. If, however, the electric connections between the circuit substrates PCB1 and PCB2 are to be taken by using the joiners JN, one circuit substrate PCB2 is formed into not a rectangular shape but a special shape having a projection, as shown in FIG. 46. This shape is followed by problems that the extraction efficiency of the circuit substrate is not satisfactory to raise the production cost of the circuit substrate.
An eleventh target of the present invention is to solve the above-specified problem.
In the outer peripheral portion of the liquid crystal display panel, on the other hand, there are arranged a plurality of divided circuit substrates, which are electrically connected by one joiner.
In accordance with development of recent years in the multiple colors of the color liquid crystal display device, the number of video signal lines for designating the gradations of red, green and blue colors increases together with the number of gradation voltages so that the portion having the function of the interface between that liquid crystal display device and the data processing device side of the personal computer or the like to be assembled with that liquid crystal display device is so complicated as to make difficult the electric connections between the drain side circuit substrate and the interface circuit substrate. Moreover, not only the number of video signal lines but also the number of connection lines are increased in accordance with the abrupt increase in the number of colors of the liquid crystal display device, because the connection lines effect the connections of the gradation voltages increasing in proportion to the color number, the clock and the power supply voltage.
As the number of connection lines thus increases, the space for mounting the joiners is enlarged to raise a problem that said device is large-sized.
A twelfth target of the present invention is to solve the above-specified problem.
On the other hand, the mounting holes, as formed in the liquid crystal display device for mounting the display device as the display unit in the data processing device such as the personal computer or word processor, are usually formed in the corners of the metallic shield casing at the portions (as will be called the xe2x80x9cdrawn portionsxe2x80x9d), which are integral with the metal plate forming said shield casing and drawn to form a parallel plane at a level different from the metal plate. In case the corners of the shield casing are drawn, the drawn portions can be reduced generally to a quadrant by removing the side face of the shield casing at said corners. However, from the relation to the arrangement of the packaged parts of the circuit substrate or the electric connections of the circuit substrates, however, it is demanded to form the mounting holes not at the corners but in the intermediate portions spaced at a considerable distance from the corners. In this case, the shape of the drawn portions of the mounting holes cannot be made quadrant but semicircular from the conveniences of the drawing operations. As a result, the area necessary for the mounting holes is enlarged to invite disadvantages in reducing the size and weight of the liquid crystal display device.
A thirteenth target of the present invention is to solve the above-specified problem.
In the latest years, on the other hand, there is a problem that the liquid crystal display device emits harmful radiative electric waves which cause the EMI (i.e., electromagnetic interference). It is, therefore, urgent from the safe drives of airplane, ships or automobiles handling the electric waves to reduce the EMI.
A fourteenth target of the present invention is to solve the above-specified problem.
In order to prevent the aforementioned EMI, there has been proposed in Japanese Patent Application No. 53496/1992 a technique in which the circuit substrate arranged on the outer peripheral portion of a liquid crystal display panel is equipped on its face with frame ground pads connected with ground wiring lines and in which pawls (or slender projections) formed by noting a metallic shield casing partially are soldered to the frame ground pads. According to this technique, the ground wiring lines of the circuit substrate are connected with the common metallic shield casing having a sufficiently low impedance so that the ground wiring lines can be strengthened in the higher frequency range to suppress the emission of the harmful radiative electric waves. In this prior art, however, the shield casing is formed with the pawls on its upper face (i.e., the so-called frame portion around the display) so that the pawls may come, when folded toward the circuit substrate, into abutment against the circuit substrate, thus raising a problem that the folding workability is poor. Since, moreover, the pawls are to be soldered to the frame ground pads, the soldering operations have to be carried out through the small openings around the pawls after the shield casing has been attached to cover the circuit substrate. This also deteriorates the soldering workability.
A fifteenth target of the present invention is to solve the above-specified problems.
In the liquid crystal display device of the prior art, on the other hand, the video signal lines are alternately extracted above and below the liquid crystal display panel, and two video signal line driving circuit substrates to be connected with the input terminals of the extracted video signal lines are individually arranged on the upper and lower sides of the outer peripheral portion of the liquid crystal display panel where as the electronic parts are arranged along the flow of the signals which are fed from an external personal computer through said device. As a result, a connector to be connected with the personal computer or the like and a signal source integrated circuit are arranged at the central portion of an interface circuit substrate. Incidentally, if the arrangement of the electronic parts along the signal flow of the aforementioned system is taken in case the video signal lien driving circuit substrate is arranged at only one side of the liquid crystal display panel, then the layout is made such that the connector is arranged at the remote end portion of the interface circuit substrate from the video signal line driving circuit substrate, i.e., at the end portion closest to the corner of the metallic shield casing for accommodating the liquid crystal display panel and the circuit substrate, and such that the signal source integrated circuit is arranged adjacent to the connector in the direction apart from the corner. If the connector is then to be arranged at the remotest end of the interface circuit substrate, i.e., in the vicinity of the corner of the shield casing, the corners of the metallic shield casing having the mounting hole are covered with the mold casing having the aligned mounting holes because the connector cannot be covered with the monolithic mold casing to be united with the metallic shield casing so that it may be connected with the personal computer or the like. As a result, the two casings cannot be fixed by fastening them by threading the screws or the like through those mounting holes. As a result, the mechanical strength is deteriorated to raise a problem that the reliability is lowered.
A sixteenth target of the present invention is to solve the above-specified problem.
In order to suppress the emission of the unnecessary radiative electric waves to cause the EMI, a plurality of resistors and capacitors for smoothing the signal wave forms are discretely arranged in the prior art in the vicinity of the signal source integrated circuit or in the course of the signal transmission route. As a result, there are required several spaces for interposing the resistors and capacitors in the vicinity of the signal source integrated circuit and between the tape carrier package mounting the driving IC chips, so that the dead spaces are so enlarged that the electronic parts cannot be packaged in a high density.
A seventeenth target of the present invention is to solve the above-specified problem.
A first object of the present invention is to provide a liquid crystal display device and a data processing device, which can be small-sized and light-weighted by reducing the area of the frame portion.
A second object of the present invention is to provide a liquid crystal display device which can firmly hold the liquid crystal display panel to have a high mechanical strength.
A third object of the present invention is to provide a liquid crystal display device which can be small-sized and light-weighted by efficiently accommodating a fluorescent tube of a back light.
A fourth object of the present invention is to provide a liquid crystal display device which can be small-sized and light-weighted by firmly holding a light guide plate and a liquid crystal display panel in the device.
A fifth object of the present invention is to provide a liquid crystal display device which can be small-sized and light-weighted by holding the cables of the fluorescent tube while being prevented from bulging out of the liquid crystal display device.
A sixth object of the present invention is to provide a liquid crystal display device which can be small-sized and light-weighted by efficiently holding the light guide plate in the device and by reducing the size of the light guide plate as small as possible.
A seventh object of the present invention is to provide a liquid crystal display device which can be small-sized and light-weighted by suppressing the bulging of the bottom face of a mold casing due to the weight of the liquid crystal display panel, the light guide plate or the like and by thinning the mold casing.
An eighth object of the present invention is to provide a liquid crystal display device which can be small-sized and light-weighted by confining the cables and the inverter within the device.
A ninth object of the present invention is to provide a liquid crystal display device which can realize the multigradation, the single power source and the compact packaging by solving the problem of heat liberation of the parts on the circuit substrate.
A tenth object of the present invention is to provide a liquid crystal display device which can reduce the number of electronic parts and the number of working steps to reduce the production cost.
An eleventh object of the present invention is to provide a liquid crystal display device which can have a high extraction efficiency of the circuit substrate to reduce the cost for the material of the circuit substrate.
A twelfth object of the present invention is to provide a liquid crystal display device which can be small-sized and light-weighted by connecting the circuit substrate in a small space even in case the number of connections between the circuit substrates is large.
A thirteenth object of the present invention is to provide a liquid crystal display device which can be small-sized and light-weighted by reducing the drawn portions of the mounting holes generally to a quadrant in case the mounting holes are to be formed in the intermediate portions of the shield casing.
A fourteenth object of the present invention is to provide a liquid crystal display device which can suppress emission of harmful radiative electric waves.
A fifteenth object of the present invention is to provide a liquid crystal display device which can have satisfactory folding and soldering workabilities of the pawls formed integral with the shield casing.
A sixteenth object of the present invention is to provide a liquid crystal display device which can have a high mechanical strength and a high reliability.
A seventeenth object of the present invention is to provide a liquid crystal display device which can reduce the dead space to package the electronic parts highly densely when the resistors and capacitors are mounted for the countermeasures of the EMI.
Means for Solving the Problems
In order to solve the aforementioned first problem, the liquid crystal display device of the present invention is characterized in that a video signal line driving circuit substrate is arranged on only one of the longer sides of the display panel and is connected with the terminals of the video signal lines.
Moreover, a liquid crystal display device comprising a liquid crystal display panel, in which first and second insulating substrates are superposed at a predetermined gap such that their faces respectively formed with transparent pixel electrodes and an orientation film are opposed to each other, in which the two substrates are adhered to each other through a seal member applied in a frame shape on the edge portions between the two substrates while sealing a liquid crystal in the seal member between the two substrates, and in which a plurality of scanning signal lines and video signal lines arrayed on the opposed face of the first insulating substrate have their individual terminals disposed outside of the seal member, characterized in that a video signal line driving circuit substrate is arranged on only one of the longer sides of the display panel and is connected with the terminals of the video signal lines.
Moreover, a liquid crystal display device comprising a liquid crystal display panel in which there are superposed at a predetermined gap: a first insulating substrate including a plurality of scanning signal lines extending in a horizontal direction and arranged in a vertical direction and a plurality of video signal lines extending in a vertical direction and arranged in a horizontal direction, and having a first pixel electrode and a switching element at the intersecting regions between the two adjacent ones of the scanning signal lines and the two adjacent ones of the video signal lines; and a second insulating substrate having a second pixel electrode opposed to the first pixel electrode, and in which a liquid crystal is sealed between the two substrates, characterized in that a video signal line driving circuit substrate is arranged on only one of the longer sides of the display panel and is connected with the terminals of the video signal lines.
Moreover, a liquid crystal display device is characterized in that no circuit substrate is arranged at the other side of the display panel which is arranged with the video signal line driving circuit substrate.
Moreover, a liquid crystal display device is characterized in that two sides perpendicular to the side of the display panel, which is arranged with the video signal line driving circuit substrate, is arranged at one side with a scanning signal line driving circuit substrate and at the other with a circuit substrate including a power source circuit and a conversion circuit.
Moreover, the liquid crystal display device is characterized in that the video signal lien driving circuit substrate is arranged above the display of a display unit when the liquid crystal display device is assembled as the display unit in a predetermined data processing device.
In order to solve the aforementioned second problem, moreover, a liquid crystal display device according to the present invention is characterized in that the liquid crystal display panel sealing a liquid crystal between the two superposed insulating substrates is formed with a single plate portion so that the liquid crystal display panel is held through an elastic member between on at least one of the upper and lower faces of the single plate portion and fixed in the device.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel sealing a liquid crystal between two superposed transparent glass substrates; a circuit substrate arranged on the outer peripheral portion of the liquid crystal display panel; and a back right arranged below the liquid crystal display panel, characterized: in that a metallic shield casing for accommodating the liquid crystal display panel and the circuit substrate and a mold casing monotlithically molded for accommodating the back light are united by their individual fitting portions; and in that the liquid crystal display panel is held through an elastic member on a single plate portion formed on the liquid crystal display panel and is fixed in the device.
Moreover, the liquid crystal display device is characterized in that the elastic member is interposed between the single plate portion of the liquid crystal display panel and the back light.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel sealing a liquid crystal between two superposed transparent glass substrates; circuit substrates arranged at the two, three or four sides of the peripheral portion of the liquid crystal display panel; a light guide plate for a back light arranged below the liquid crystal display panel; a metallic shield casing for accommodating the liquid crystal display panel and the circuit substrates; and a mold casing monolithically molded for accommodating the back light, the metallic shield casing and the mold casings being united by fitting their individual fitting members, characterized in that the liquid crystal display pane is formed with a single plate portion so that the liquid crystal display panel and the light guide plate are held through an elastic member between the single plate portion and the light guide plate and fixed in the device.
Moreover, a liquid crystal display device is characterized in that a double sided adhesive sheet is sandwiched between the liquid crystal display panel and the metallic shield casing.
Moreover, a liquid crystal display device is characterized in that the single plate portion is formed on the three sides or the entire periphery of the liquid crystal display panel although it is intrinsically necessary to arrange the terminal electrodes.
In order to solve the aforementioned third problem, moreover, the present invention is characterized in that the fluorescent tube of the back light is arranged below a plurality of tape carrier packages arranged on the outer peripheral portion of the liquid crystal display panel.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel; a light guide plate arranged below the liquid crystal display panel; a fluorescent tube arranged in the vicinity of at least one side face of the light guide plate; and a plurality of tape carrier packages arranged on the outer peripheral portion of the liquid crystal display panel, characterized in that the fluorescent tube is arranged below the plurality of tape carrier packages.
Moreover, a liquid crystal display device is characterized in that one of the longer sides of the liquid crystal display panel and one of the shorter sides of the liquid crystal display panel are formed only on their outer peripheral portion with a plurality of the tape carrier packages, below which is arranged the fluorescent tube.
In order to solve the aforementioned fourth problem, a liquid crystal display device comprising: a liquid crystal display panel; a light guide plate arranged below the liquid crystal display panel; a fluorescent tube arranged in the vicinity of the side face of the light guide plate; at least one optical sheet arranged on the upper face of the light guide plate; a casing for accommodating the light guide plate and the fluorescent tube, characterized: in that the side portions of the at least one optical sheet are protruded from and placed on the side wall of the casing; and in that an elastic member such as a rubber cushion is interposed between the optical sheet on the side wall and the liquid crystal display panel.
Moreover, a liquid crystal display device is characterized in that the elastic member is sandwiched between the optical sheet on the side wall and the upper transparent glass substrate of the liquid crystal display panel.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel; a circuit substrate arranged in the outer peripheral portion of the liquid crystal display panel; a light guide plate arranged below the liquid crystal display panel; a fluorescent tube arranged in the vicinity of at least one side face of the light guide plate; at least one optical sheet arranged on the upper face of the light guide plate; a metallic shield casing accommodating the liquid crystal display panel and the circuit substrate; and a mold casing monolithically molded and accommodating the light guide plate and the fluorescent tube together, characterized: in that at least one of the four sides of the at least one optical sheet has its end portion protruded and placed on the side wall of the mold casing; in that an elastic member is interposed between the optical sheet on the side wall and the lower face of an upper transparent glass substrate of the liquid crystal display panel; and in that the shield casing and the mold casing are united by fitting their individual fitting portions.
Moreover, a liquid crystal display device is characterized in that the optical sheet is a diffusive sheet mounted on the upper face of the light guide plate, and a prism sheet formed on the upper face of the diffusive sheet.
In order to solve the aforementioned fifth problem, according to the present invention, a liquid crystal display device comprises a back light having a fluorescent tube and cables of the fluorescent tube, characterized by a holding member having an elastic member for holding both the fluorescent tube and the cables.
Moreover, a liquid crystal display device comprises a back light including a fluorescent tube and two cables having their individual one ends connected with the two ends of the fluorescent tube and their other ends extracted in a common direction, characterized in that a retaining member is formed one or more holes or grooves for holding both the fluorescent tube and one or two of the cables.
In order to solve the aforementioned sixth problem, according to the present invention, a liquid crystal display device in which a light guide plate for a back light arranged below a liquid crystal display panel and a fluorescent tube arranged in the vicinity of the side face of the light guide plate are accommodated in a casing, is characterized in that the light guide plate is prevented from moving toward the fluorescent tube by small projections which are formed on the inner face of the casing between the light guide plate and the fluorescent tube.
Moreover, a liquid crystal display device is characterized in that the casing is a monolithic mold casing.
Moreover, a liquid crystal display device is characterized in that the light guide plate is generally rectangular.
Moreover, a liquid crystal display device is characterized in that the light guide plate has a size as similar to that of an effective light emitting portion as possible.
Moreover, a liquid crystal display device is characterized in that the projections are integral with the casing.
Moreover, a liquid crystal display device is characterized in that two projections are formed in the vicinity of the two end portions of the fluorescent tube.
Moreover, a liquid crystal display device is characterized in that the three sides of the light guide plate other than one at the side of the fluorescent tube are held by the inner wall of the a light guide plate accommodating portion which is formed in the casing along the generally rectangular shape of the light guide plate.
In order to solve the aforementioned seventh problem, according to the present invention, a liquid crystal display device is characterized in that an opening is formed at a central portion except for the frame portion of the casing for holding a light guide plate.
Moreover, a liquid crystal display device, in which a liquid crystal display panel and a light guide plate arranged below the former are accommodated in a monolithic mold casing and a metallic shield casing, is characterized in that an opening is formed at a central portion except for the frame portion of the mold casing.
Moreover, a liquid crystal display device comprising: a metallic shield casing for accommodating a liquid crystal display panel; a mold casing monolithically molded for accommodating a light guide plate to be arranged below the liquid crystal display panel; and an elastic member interposed between the liquid crystal display panel and the light guide plate, wherein the shield casing is pushed into the device to unit the shield casing and the mold casing by fitting their individual fitting portions, is characterized in that the mold casing is formed with an opening at its central portion excepting its frame portion.
In order to solve the aforementioned eighth problem, according to the present invention, a liquid crystal display device is characterized in that the cables of the back light are fitted in a groove formed in the casing.
Moreover, a liquid crystal display device comprising: a fluorescent tube; and a monolithic mold casing for accommodating the fluorescent tube, is characterized in that two cables connected wit the two ends of the fluorescent tube are fitted in a groove formed in the mold casing.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel; a circuit substrate arranged on the outer circumferential portion of the liquid crystal display panel; a light guide plate arranged below the liquid crystal display panel; a fluorescent tube arranged on at least one side face of the light guide plate; a metallic shield casing for accommodating the liquid crystal display panel and the circuit substrate together; and a mold casing monolithically molded for accommodating the light guide plate and the fluorescent tube, is characterized in that two cables having their individual one ends connected with the two ends of the fluorescent tube are accommodated in a groove which is made integral with the side wall of the mold casing.
Moreover, a liquid crystal display device is characterized in that the first cable connected with the first end portion of the fluorescent tube is fitted in the groove formed in the side wall of the mold casing along the fluorescent tube.
Moreover, a liquid crystal display device is characterized: in that the first cable connected with the first end portion of the fluorescent tube is fitted in the groove formed in the side wall of the mold casing along the fluorescent tube; and in that the first cable downstream of the second end portion of the fluorescent tube and a second cable connected with the end portion are extracted generally perpendicularly of the direction of the first cable upstream of the second end portion.
Moreover, a liquid crystal display device is characterized in that the first cable downstream of the second end portion of the fluorescent tube and the second cable connected with the second end portion are extracted between the mounting holes of the mold casing and a circuit substrate arranged on the outer peripheral portion of the shorter side of the liquid crystal display panel.
Moreover, a liquid crystal display device is characterized in that an inverter connected with each other end of the cable is accommodated in an accommodating portion outside of the light guide plate, as formed in the mold casing, without bulging out of the mold casing.
In order to solve the aforementioned ninth problem, according to the present invention, a liquid crystal display device is characterized in that a notch is formed in a portion corresponding an exothermic portion.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel; circuit substrate arranged at three or four side of the outer peripheral portion of the liquid crystal display panel; an a casing is characterized in that a notch is formed in the casing at a portion corresponding to the exothermic portion on the circuit substrates.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel; circuit substrates arranged at three or four sides of the outer peripheral portion of the liquid crystal display panel; a back light arranged below the liquid crystal display panel; a metallic shield casing for accommodating the liquid crystal display panel and the circuit substrates together; and a mold casing monolithically molded for accommodating the back light, wherein the metallic shield casing and the mold casing are united, is characterized in that the mold casing is notched at a portion corresponding to an exothermic portion mounted on the circuit substrates.
In order to solve the aforementioned tenth problem, moreover, according to the present invention, a liquid crystal display device comprising: a liquid crystal display device panel; and a circuit substrate formed with a circuit for driving the liquid crystal display panel, is characterized in that a hybrid integrated circuit formed by hybridly integrating a portion of the circuit is packaged in the circuit substrate.
Moreover, a liquid crystal display device is characterized in that electronic parts are packaged on the circuit substrate between the circuit substrate and the hybrid integrated circuit.
In order to solve the aforementioned eleventh problem, according to the present invention, a liquid crystal display device comprising: a liquid crystal display panel; a plurality of divided circuit substrates arranged on the outer peripheral portion of the liquid crystal display panel and electrically connected by joiners; a casing for accommodating the liquid crystal display panel and the circuit substrates together; and mounting holes formed in the casing for the device, is characterized in that at least one of the mounting holes is arranged away from the corner of the casing.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel; circuit substrates divided and arranged at the two, three or four sides of the outer peripheral portions of the liquid crystal display panel; and a casing for accommodating the liquid crystal display panel and the circuit substrates together and formed with mounting holes, is characterized: in that at least one of the mounting holes is arranged at a distance from the corner of the casing; and in that the circuit substrate having a generally rectangular shape are divided into a plurality of sheets and are electrically connected in the vicinity of the corners by joiners.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel; a plurality of divided circuit substrates arranged at two, three or four sides of the outer peripheral portion of the liquid crystal display panel; a back light arranged below the liquid crystal display panel; a metallic shield casing for accommodating the liquid crystal display panel and the circuit substrates together; and a mold casing monolithically molded for accommodating the back light, wherein the shield casing and the mold casing are united, is characterized: in that at least one of the mounting holes is arranged at a distance from the corners of the shield casing and the mold casing; and in that the circuit substrate having a generally rectangular shape are divided into a plurality of sheets and are electrically connected in the vicinity of the corners by joiners.
In order to solve the aforementioned twelfth problem, according to the present invention, a liquid crystal display device comprising a plurality of circuit substrates, is characterized in that the circuit substrates are electrically connected with each other by two or more electric connection means superposed at two or more stages.
Moreover, a liquid crystal display device comprising circuit substrates divided into a plurality and arranged at the two, three or four sides of the outer circumferential portion of a liquid crystal display panel, is characterized in that the circuit substrates are electrically connected with each other through at least two joiners which are superposed at two or more stages in the thickness direction of the display device.
Moreover, a liquid crystal display device is characterized in that one of the plurality of electrically connected circuit substrates is an interface circuit substrate.
In order to solve the aforementioned thirteenth problem, according to the present invention, a liquid crystal display device having a metallic casing formed with mounting holes, is characterized: in that the mounting holes are positioned at intermediate portions spaced at a predetermined distance from the corners of the casing and in a drawn portion which is made integral with a metallic plate forming the casing and which forms a parallel plane at a different level as that of the metal plate; in that the drawn portion is given generally a quadrant shape; and in that the quadrant shape is formed with a notch in its radial portion between the drawn portion and the metal plate adjacent to the drawn portion.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel; circuit substrates arranged at two, three or four sides of the outer peripheral portion of the liquid crystal display panel; a back light arranged below the liquid crystal display panel; a metallic shield casing for accommodating the liquid crystal display panel and the circuit substrates; and a monolithic mold casing for accommodating the back light, in which the shield casing and the mold casing are united, and in which the shield casing and the mold casing are formed with mounting holes aligned with each other, is characterized: in that the mounting holes are positioned at intermediate portions spaced at a predetermined distance from the corners of the shield casing and in a drawn portion which is made integral with a metallic plate forming the shield casing and which forms a parallel plane at a different level as that of the metal plate; in that the drawn portion is given generally a quadrant shape; and in that the quadrant shape is formed with a notch in its radial portion between the drawn portion and the metal plate adjacent to the drawn portion.
In order to solve the aforementioned fourteenth and fifteenth problems, according to the present invention, a liquid crystal display device is characterized: in that the circuit substrates are formed with a frame ground pad on at least one portion thereof; and in that a pawl made integral with the side face of the shield casing is connected with the frame ground pad.
Moreover, a liquid crystal display device comprising: a liquid crystal display panel; circuit substrates disposed at the two, three or four outer peripheral portions of the liquid crystal display panel; and a metallic shield casing accommodating the liquid crystal display panel and the circuit substrates and having a display window for exposing the liquid crystal display panel to the outside, characterized: in that the circuit substrates are formed with a frame ground pad on at least one portion thereof; and in that a pawl made integral with the side face of the shield casing is connected with the frame ground pad.
Moreover, a liquid crystal display device is characterized: in that the pawls are formed by cutting a portion of the side face; and in that the pawls are connected by folding inward of the liquid crystal display device.
Moreover, a liquid crystal display device is characterized in that the pawl and the frame ground pad are soldered to each other.
Moreover, a liquid crystal display device is characterized in that the circuit substrate is divided into a plurality of sheets.
In order to solve the aforementioned sixteenth problem, according to the present invention, a liquid crystal display device comprising: a first circuit substrate arranged outside of a first side of a liquid crystal display panel for driving signal lines; a second circuit substrate arranged outside of a second side adjacent to and perpendicular to the first side and having a connector for connection with the outside; a casing having a mounting hole in the vicinity of its corner for accommodating the liquid crystal display panel and the first and second circuit substrates together, is characterized: in that the first casing and the second casing are united together; in that the second circuit substrate is equipped with an electronic part having a lower height at its end portion farther from the first circuit substrate; and in that the connector is arranged adjacent to the electronic part in the direction apart from the end portion.
Moreover, a liquid crystal display device comprising: a first circuit substrate arranged outside of a first side of a liquid crystal display panel for driving signal lines; a second circuit substrate arranged outside of a second side adjacent to and perpendicular to the first side and having a connector for connection with the outside; a first casing having a first mounting hole in the vicinity of its corner for accommodating the liquid crystal display panel and the first and second circuit substrates; a back light disposed below the liquid crystal display panel; and a second casing having a second mounting hole aligned with the first mounting hole for accommodating the back light, is characterized: in that the first casing and the second casing are united together; in that the second circuit substrate is equipped with an electronic part having a lower height at its end portion farther from the first circuit substrate; and in that the connector is arranged adjacent to the electronic part in the direction apart from the end portion.
Moreover, a liquid crystal display device is characterized in that no circuit substrate is arranged outside of the third side opposed to the first side of the liquid crystal display panel arranged with the first circuit substrate.
Moreover, a liquid crystal display device is characterized: in that the first circuit substrate is a video signal line driving circuit substrate; and in that a scanning signal line driving circuit substrate is arranged at the fourth side opposed to the second side of the liquid crystal display panel arranged with the second circuit substrate.
Moreover, a liquid crystal display device is characterized in that the second circuit substrate is an interface circuit substrate having a power source circuit and a conversion circuit.
Moreover, a liquid crystal display device is characterized in that the lower electronic parts are a signal source integrated circuit.
In order to solve the aforementioned seventeenth problem, according to the present invention, a liquid crystal display device is characterized in that a plurality of electronic parts for counter-measures of the EMI are concentratedly arranged on the circuit substrate.
Moreover, a liquid crystal display device is characterized in that a plurality of capacitors and resistors for the counter-measures of the EMI are concentratedly arranged at the end portion of the circuit substrate apart from the signal source integrated circuit and downstream of the flow direction of a drive IC chip.
Moreover, a liquid crystal display device comprising circuit substrates arranged at two, three or four sides of the outer peripheral portion of a liquid crystal display panel, is characterized in that a plurality of capacitors and resistors for the counter-measures of EMI are concentratedly arranged apart from a signal source integrated circuit and at the end portion of the circuit substrate downstream in the direction of signal flow of a drive IC chip.
Operations
In the liquid crystal display device of the present invention, the terminals of the video signal lines are extracted to only one side of the liquid crystal display panel, and the video signal line driving circuit substrate to be connected with the terminals is arranged at the side of the display panel, usually at only one longer side. As a result, the area of the frame portion around the display unit can be reduced to reduce the size and weight of the liquid crystal display device and the data processing device assembling the former. Moreover, when the liquid crystal display device is packaged as the display unit in the data processing device such as a personal computer or word processor, the side, at which the video signal line driving circuit substrate is arranged, is located at the upper side of the display. In the notebook type personal computer or word processor having the display unit hinged to the keyboard portion, a space for attaching the hinges to the lower portion of the display can be easily retained to make the vertical position of the display proper.
In the liquid crystal display device of the present invention, moreover, one of the two insulating substrates constituting the liquid crystal display panel is protruded and formed with the single plate portion and is exclusively held through the elastic member mounted on the single plate portion, so that the gap between the two substrates is not changed to cause no display unevenness even if strongly pushed. As a result, the pushing force of the liquid crystal display panel can be increased to improve the mechanical strength and the reliability.
In the liquid crystal display device of the present invention, moreover, the slender fluorescent tube is arranged in the space below the plurality of tape carrier packages packaged on the outer peripheral portion of the liquid crystal display panel so that it can be accommodated in a high space using efficiency. As a result, the device can have its external size reduced to reduce the size and the weight.
In the liquid crystal display device of the present invention, moreover, the end portion of at least one optical sheet such as a diffusive sheet or a prism sheet arranged on the light guide plate is protruded from the end portion of the side of the light guide plate and placed on the side wall of the casing accommodating the light guide plate, and the elastic member such as a rubber cushion is sandwiched between the optical sheet on the side wall and the liquid crystal display panel and is firmly held by the casing, so that the light guide plate and the liquid crystal display panel can be firmly held and fixed in the device. Moreover, this holding structure can reduce the external size of the device and accordingly the size and weight of the same. Incidentally, the elastic member such as the rubber cushion is effective to prevent the display unevenness due to the change in the gap between the two transparent glass substrates constituting the liquid crystal display panel, because one of these substrates is pushed if the elastic member is sandwiched between the optical sheet on the side wall of the casing and the upper one of the two transparent glass substrates.
In the liquid crystal display device of the present invention, moreover, both the fluorescent tube and the cables of the former are held by the holding member such as the rubber bushes made of an elastic member. As a result, the cable can be accommodated in the liquid crystal display device without bulging out, so that the liquid crystal display device can be small-sized and light-weighted to reduce the production cost.
In the liquid crystal display device of the present invention, moreover, the size of the light guide plate of the back light is made as small as that of the effective light emitting unit so that the electronic parts can be packaged in the space which has been occupied by the light guide plate of the prior art. At the same time, the light guide plate is held by the small projections formed on the inner face of the casing accommodating the light guide plate so that the light guide plate can be held in the small space. As a result, the device can be small-sized and light-weighted to reduce the production cost.
In the liquid crystal display device of the present invention, moreover, a large opening is formed in the bottom face of the mold casing at a central portion other than the surrounding frame portion so that the bottom face of the mold casing can be prevented, by the weight and internal pressure of the liquid crystal display panel, after the assembly of the liquid crystal display device, from being bulging out by the force to be applied vertically downward to the bottom face of the mold casing. As a result, the mold casing can be thinned to reduce the thickness and weight of the liquid crystal display device.
In the liquid crystal display device of the present invention, moreover, the two cables, as connected with the two ends of the fluorescent tube of the back light, are fitted in the groove formed in the casing, and the inverter is accommodated in the accommodating portion formed in the mold casing outside of the light guide plate, so that the cables and the inverter can be accommodated without bulging out of the device. As a result, the liquid crystal display device can be small-sized and light-weighted to reduced the production cost.
In the liquid crystal display device of the present invention, moreover, a notch is formed in the casing at a portion corresponding to the exothermic portion. As a result, it is possible to provide a liquid crystal display device having such a circuit as can improve not only the heat liberation of the exothermic portions, the highly dense packageability of the circuit and the compactness and as can realize the multi-gradation, the single power source and the compact packaging.
In the liquid crystal display device of the present invention, moreover, the hybrid integrated circuit, as prepared by hybridly integrating a portion of the circuit for driving the liquid crystal display panel, is packaged on the circuit substrate so that the number of the electronic parts can be reduced. At the same time, neither another circuit substrate nor any joiner is required, it is possible to reduce the cost for the material and the number of working steps. As a result, the production cost can be reduced to improve the reliability of the product.
In the liquid crystal display device of the present invention, moreover, by positioning the mounting holes of the casing away from the case corners, the space for electrically connecting the circuit substrate by the joiners can be retained while being left generally rectangular, so that the extraction efficiency of the circuit substrates can be made high to reduce the cost for the material of the circuit substrates.
In the liquid crystal display device of the present invention, moreover, the space of the device in the thickness direction can be effectively exploited to electrically connect the plurality of circuit substrates by two or more electric connection means superposed at two or more stages. As a result, the circuit substrates can be connected in a small space, even if the number of their connection lines is large, to reduce the size and weight of the liquid crystal display device.
In the liquid crystal display device of the present invention, moreover, the mounting holes can be formed, if intended so, in the intermediate portions at a predetermined considerable distance from the corners of the metallic casing by notching the radial portion of a quadrant between the drawn portions to be formed with the mounting holes and the metal plate adjacent to the former, to draw the drawn portions generally into the quadrant. As a result, the liquid crystal display device can be small-sized and light-weighted.
In the liquid crystal display device of the present invention, moreover, the pawls, as integrally formed by notching the metallic shield casing, are connected with the frame ground pads which are connected with the ground wiring lines and formed on the face of the circuit substrate. As a result, the ground wiring lines are connected with the common metallic shield casing having a sufficiently low impedance so that the they are strengthened in a higher frequency range to suppress the emission of the harmful radiative electric waves.
Since, moreover, the pawls are formed on the side of the shield casing, they are kept, when folded, away from any contact with the circuit substrate unlike the pawls formed on the upper face, so that the workability is satisfactory. In case, on the other hand, the pawls are soldered to the frame ground pads, the circuit substrate, as united with the liquid crystal display panel, can be soldered from the inner face of the open shield casing after it has been fixed in the shield casing, so that the soldering workability is excellent.
In the liquid crystal display device of the present invention, moreover, the electronic parts of the signal source integrated circuit, as have a low level, are arranged at the remotest end of the circuit substrate having the connector with the outside, that is, over the circuit substrate in the vicinity of the corner of the casing for accommodating the circuit substrate and the liquid crystal display panel, and the connector is arranged adjacent thereto in the direction apart from the corner. As a result, the vicinity of the corner of the casing, as formed with the mounting holes, can be covered with the case integral with or separate from the aforementioned casing. When the device is packaged in the data processing device such as a personal computer, the corner of the casing of the device is firmly held and fixed through the mounting holes by the screws or the like so that the mechanically strength can be improved to improve the reliability of the product.
In the liquid crystal display device of the present invention, moreover, a plurality of electronic parts for counter-measures of the EMI are arranged concentratedly on the circuit substrate so that the dead space can be reduced to package the electronic parts highly densely. As a result, the liquid crystal display device can be small-sized and light-weighted to reduce the production cost.